Electrical apparatus



April 29, 1941.

D. F. ALEXANDER ETAL ELECTRICAL APPARATUS Original Filed March 4, 1937kwltbxw v ENTORS Aa N m Patented Apr. 29, 1941 ELECTRICAL APPAB-A'IUSDonald F. Alexander, Charles F. Henney, and Charles L. Paulus, Dayton,Ohio, assignorl to General Motors Corporation Dayton, Ohio, a

corporation of Delaware Original application March 4, 1937, Serial No.129,024. Divided and this application August 20, 1937, Serial No.160,148

2 Claims. (Cl. 171-313) This invention relates to refrigeration, andmore particularly to the conditioning of air in railway cars or thelike. This application is a division of our copending application SerialNo.

129,024, filed March 4, 1937, now Patent No.

2,104,382, and is a continuation in part of our copending applicationSerial No. 118.816, filed January 2, 1937, now Patent No. 2,104,148.

In our copending application, Serial No. 118,816, we. have disclosed theconditioning of air by a refrigerant which is circulated by a compressorand in which a dynamo-electric machine and the compressor are drivenfrom the and also drives the compressor if refrigeration is' required insuch a manner that both the compressor and dynamo-electric machine maybe driven at the same time. Reference is hereby made to the saidcopending application Serial No. 118,816 for further disclosure thereof.

The foregoing system is particularly advantageous where the car ishauled by any type of locomotive, such as a steam locomotive, since theentire system is a unitary structure within the car and is independentof the type of locomotive. Occasionally, however, a car may be hauledduring a part of a run by a steam locomotive, and during another part ofthe run it may be hauled by a locomotive or car uhich is electricallyenergized either from an overhead wire system or by electrical powerderived from an internal combustion engine and generator on thelocomotive. The present invention permits a portion of the airconditioning system and/or the battery charging system to be directlyconnected to the outside source 01' electrical energy which drives thelocomotive or car and thus removes a certain amount of tractive loadfrom the wheels of the car. This is particularly desirable because thetractive power of electric locomotives or cars falls oil rapidly at highspeeds and it is desirable to reduce the tractive load therefrom. Thisimprovement is also adapted for use when outside electrical energy isavailable only at the station, as for "stand by" service.

In the preferred modification of our invention, a separatedynamo-electric machine unit or similar current rectifying or voltagereducmg device automatically is started whenever the outside or tractiveelectrical source of power is available, and this additionaldynamo-electric machine or device not only charges the battery of thecar, but also furnishes power to drive the original dynamo-electricmachine disclosed in our copending application Serial No. 118,816 sothat it acts as a motor to drive the compressor as long as the outsideor tractive electrical source of power is available.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawing, wherein a preferred form of the present invention is clearlyshown.

In the drawing: r

Fig. 1 is a diagrammatic representation of an air conditioning system asapplied to a railway car in which a current rectifying or voltagemodifying device is provided; and

Fig. 2 is a diagrammatic representation of the wiring system for theapparatus shown in Fig. 1, together with the necessary cooperating partsdisclosed in our copending application, Serial No. 118,816.

Referring to Fig. l, a railway car In is provided with a live axleassembly H which may include one or more axles of the car. The car i0 isprovided with a compartment to be cooled. For this purpose, anevaporator I2 is provided over which a current of air is blown by meansof a fan 13 driven by a motor It. The refrigerant for the evaporator i2is circulated or liquefled by the refrigerant circulating or liquefyingunit l5 preferably comprising a compressor 16 and condenser l'l. Air isblown over thecondenser I! by means of the fan l8 driven by the motorl9. On abnormally warm days, water is sprayed over the condenser H bymeans of the spray device 20 under the control of the valve 2| which isactuated by the thermostatic bulb 22. Water for the spray device 20 isprovided by a tank under pneumatic pressure derived from the air-brakesystem of the car.

Operation of silstemof Figs. 1 and 2 when outside electrical energy isnot available The arrangement is such that the live axle assembly lldrives the compressor l6 together with a dynamo-electric machine 23.Preferably an automatic variable ratio transmission 24 is provided whichautomatically delivers a substantially constant drive speed to thecompressor and dynamo-electric machine after the car has attained apredetermined speed limit. If desired, an exciter 2 5 is drivenproportionally to the car speed, and this exciter is used not only toexcite generating field of the dynamo-electric machine but also tocontrol the devices which are responsive to car speed, such as thepneumatic valves 26 and 21 which control the clutches 28 and 29.

The reirigerating output of the system is controlled by an automaticswitch I which may be made responsive to any condition of air such asthe dry bulb temperature, wet bulb temperature, relative humidity or thelike either within the car or outside the car or both.

Fig. 2 shows the wiring diagram for the system. When air conditioning isdesired, the switches 3| and lid are manually closed and start the motorll which drives the tan l3. During-a first car speed zone, such as whenthe car is standing or is moving at a relatively low speed, such asbelow m. p. h. the dynamo-electric machine 23, as a motor, drives thecompressor It it retrigeration is required under the control of switch30. The switch 32 is normally closed since it is opened only in case ofabnormal head pressure by the bellows 33. The switch 32 being closed,

the solenoid 33a closes switch 34 and starts the 1 motor l9 whichactuates the condenser fan I8. If it is abnormally warm, thermostaticbulb 22 closes the switch 35 which opens the valve 2i and sprays waterover the condenser. The exciter 25 does not have a sufficient voltage tocause the solenoid 38 to actuate the arm 31 and hence the switch 38 isclosed. This energizes the solenoid 39 which closes the switch 40 with atime delay device II. The closing of switch 40 energizes solenoid 42which in turn sequentially closes the contacts 43 and places thearmature ll of dynamo-electric machine 23 across the battery. The motorfield 45 is simultaneously placed across the battery. Before thedynamo-electric machine can be started, the solenoid valve 21 isenergized and closes the clutch 29 so that the dynamoelectric machinedoes not start as a motor without a load but is connected to thecompressor.

At the nextcar speed zone, whichmay be between 15 and 30 m. p. h., thevoltage of the exciter is sufiicient to energize solenoid 36 enough tomove the contact arm 31 to the right. This movement so arranges theparts that the live axle assembly H can drive the compressor I6, iirefrigeration is required, but the dynamoelectric machine 23 isprevented from generating, as more fully expained in our copendingapplication, Serial No. 118,816. At the third, or highest, -car speedzone, the voltage of the exciter is sufliciently high to actuate thecontact arm by means 0! the solenoid 5|, and this changesthe,dynamo-electric machine into a generator, the held 45 beingenergized by the exciter 25. The arrangement is such that the compressoris driven from the live axle assembly when refrigeration is required,and the dynamo-electric machine is driven as a generator at all timesduring this highest car speed.

The foregoing operation is more fully described in our copendingapplication Serial No. 118,816, and reference is made thereto, ifnecessary, for a more detailed description-thereof.

Operation of system when outside electrical .eneray is available Inaccordance with the modification shown in Figs. 1 and 2 oi! thisapplication, when outside electrical energy is available, an electricalenergy rectifying or voltage reducing unit 52 is automatically connectedinto the system so that the battery is charged by the unit 52 and thedynamo-electric machine 23 acts only as a motor to drive the .compressorwhen refrigeration is required. For example, when the train arrives atthat portion of the line where an overhead wire system I is provided,the connector 54 is elevated into position. The primary 0! thetransformer BI is connected to the ground or axle "a and the wire 58 toinduce relatively low tension A. C. current in the secondary coil. Thislatter current passes through an A. C. motor starter I.

, and drives the A. C. motor 51 of the unit '1. The

motor I! drives the low voltage generator I. which is connected, throughthe automatic battery cut-out 59, to both sides of the battery I. Thebattery cut-out 5! automatically connects the generator 58 with thebattery when the generator 58 operates and disconnects it when it isidle. Current or power is thus provided for charging the battery and ismade available to drive the compressor through dynamo-electric machine23 as a motor under the control 0! switch 30 as previously described.When the connector 54 is elevated the solenoid 8! is energized and opensthe switch 82, This opens the circuit to the exciter held 63 andprevents the exciter II irom generating any current thus placing thewiring diagram in the equivalent position 01' zero car speed. Underthese conditions, a dynamoelectric machine 23 drives the compressor l6,under the control or automatic switch 30, at all car speeds and thedynamo-electric machine 23 is rendered incapable of acting as agenerator.

While we have shown the terminals 54 and "a specifically connected to anoverhead wire and to a rail, these may be connected to any other sourceof outside electrical energy, such as an electrical source on a Dieselengine-generator type or locomotive, or a source of electrical energy ata station.

For purposes of illustration, we have shown the outside source orelectrical energy as being an overhead wire such as 53. However, it isto be understood that the outside supply of current may be supplied byothermeans such as those more fully described in Patent No. 2,104,382,of which this application is a division.

Reference is hereby made to Patent No. 2,104,- 382, of which thisapplication is a division, for a disclosure of additional modifications.

While the form of embodiment of the invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1, In a vehicle; a live axle assembly; a unitary dynamo-electricmachine; a battery; torque transmitting means from said live axleassembly to said dynamo-electric machine; control means. automaticallyresponsive to vehicle running conditions, to cause said dynamo-electricmachine, to act as a motor energized from said battery, to motorindependently of said live axle assembly when said vehicle is standingand, when said vehicle is in motion, to cause said live axle assembly todrive, through said torque transmitting means, said dynamo-electricmachine, said dynamo-electric machine arranged to act as a generator to7 charge said battery, a source of outside alternab ing current, acurrent-changing device connectible to said source of outside electricalcurrent, connecting means for connecting said source to saidcurrent-changing device and for connecting said current-changing deviceto said battery and dynamo-electric machine, and means for modityingsaid control means when said currentchanging device is operating tocause said dynamo-electric machine to act as a motor when said car is inmotion.

2. In a vehicle;v a live a-xle assembly; a unitary dynamo-electricmachine; a battery; torque transmitting means from said live axleassembly to said dynamoelectric machine; control means,

automatically responsive to vehicle running oon-' ditions, to cause saiddynamo-electric machine, to act as a motor energized from said batteryto motor independently of said live axle assembly when said vehicle isrunning below a certain speed limit and, when said vehicle is runningabove a certain speed limit, to cause said live axle assembly to drive,through torque transmitting means, said dynamo-electric machine, saiddynamo-electric machine arranged to act as a generator to charge saidbattery, a source 01! outside electrical energy, a motor. means forenergizing said motor from said source, a generator driven by saidmotor, and additional control means responsive to the connection ofsaid. source to said motor to connect said generator to said battery anddynamo-electric machine and to cause said dynamo-electric machine tooperate as a motor.

CHARLES F. HENNEY. DONALD F. ALEXANDER. CHARLES L. PAULUS.

